Smuggling meat in luggage such as holdalls poses a major risk to human health and could spread disease, while the bushmeat trade also poses a threat to wildlife, they warned.

Dr Anne-Lise Chaber, from ZSL and the RVC, said: "Our results estimate that around 270 tonnes of potentially contaminated illegal bushmeat is passing unchecked through a single European airport per year, posing a huge potential risk to potential public health."

And the study, which is published today in the journal Conservation Letters, said the nature of the imports suggested there was a growing luxury market for the meat and it was being brought in for trade and not simply personal consumption.

Co-author Dr Marcus Rowcliffe, from ZSL, said: "Our results show that this is a lucrative, organised trade feeding into a luxury market; a 4kg monkey will cost around €100 (£84) in France, compared with just €5 (£4) in Cameroon.

"Importing bushmeat is relatively easy, as customs officials are given no financial incentives to uncover illegal meat imports, compared with the bonuses they're awarded for drug and counterfeit seizures.

"Also, penalties are very low for people caught carrying illegal meat."